One could wonder why in diabetes, a condition in which the blood sugar concentration in the blood goes up, we need to worry about the liver. Or for that matter, even take the blood sugar reports seriously at all.
Doctors have begun to realise that the elevated blood sugar value is only the tip of the iceberg. Patients with type 2 diabetes, the common form of the disease that occurs in adulthood, often go on to develop problems with several other organs of the body, such as kidneys, brain, blood vessels, heart, feet and the liver.
Why do the blood levels go up?
At the root of the problem in Type 2 Diabetes, is the question, “Why do the blood sugar levels go up?” The intuitive answer would point at a shortage of the hormone called insulin that is produced by the pancreas, and pancreas does the job of driving blood sugar levels down. But contrary to expectations, the blood levels of insulin in this condition are increased!
The answer is, therefore, complex. It starts with the recognition of the underlying condition called Insulin Resistance (IR). One finds that as time goes on, some people need higher and higher amounts of circulating insulin in the blood to push the blood glucose into cells and the sugar in check.
This is in contrast to Type 1 Diabetes that is caused by shortfall in insulin production. But the common Type 2 diabetes is characterised, at least in its early stages, by not just high blood sugar levels, but by high insulin levels too.
Insulin resistance (IR) brings with it several changes in the body such as thickening of the basement membrane, the floor on which cells of all organs of the body are lined up and pushes up fatty acids in blood circulation, which then get deposited in the liver and blood vessels.
The baggage: Liver trouble
Diabetes, therefore, affects several organs of the body, and hence does not usually come alone. It can be associated with obesity, increased blood lipids (cholesterol or triglycerides) and high blood pressure, all of which can be caused by IR as the underlying mechanism.
Diabetes affecting the kidneys, eyes, feet and heart is common knowledge. Its effects on the liver often go unnoticed.
‘Fatty Liver’ is very commonly seen in patients with Type 2 Diabetes, and can be picked up by a simple ultrasound examination in up to 70 per cent cases. This condition results from excess accumulation of fat in liver cells. The liver becomes usually enlarged and is pale and greasy to see.
Fatty liver usually has no clear symptoms in the early stages. It gets recognised during investigations for abnormal readings on liver function tests (AST , ALT or GGT levels in blood) or during an ultrasound examination.
A more reliable new test that is quick, accurate and painless is the latest version of Liver Fibroscan with CAP. This machine uses low frequency ultrasound waves, and through a new technology, is able to measure the amount of fat in the liver. It scores over ultrasound as the latter cannot quite give a measurement value with grades of mild to severe, often depending upon the impression of the sonographer.
There are other tests to estimate liver fat too. The time tested method has been liver biopsy; this procedure is however painful and requires hospitalization for a day. Other methods include a special version of MRI that uses spectroscopy to measure fat. The fibroscan has however emerged as the simplest and easiest one.
Although fatty liver disease does not produce much symptoms in the early stages, and sometimes, even when the blood tests for liver function are normal, is not an innocuous condition. Research shows that patients with extra fat in their livers die early, that is, their lives are shorter than their fat-free counterparts.
What damage does liver fat do? Some of them go on to develop a state of weakness of the liver called Liver Cirrhosis. In this condition, liver cells die insidiously and are replaced by scar tissue. The organ gradually starts functioning poorly, sometimes causing swelling of feet or retention of water in the abdomen. The veins in the food pipe can get engorged and rupture, causing blood vomiting.
When the liver gets very weak due to Liver Cirrhosis, transplantation of the diseased organ is sometimes required. This condition is getting so common that it makes up around a third of all causes of liver transplantation.
Why the disease progresses rapidly in some and goes slow in others is not always evident. Understandably, those who also have other contributory factors such as obesity, excess alcohol consumption, hypertension or elevated blood cholesterol levels are more likely to progress rapidly. But doctors still do not know for sure why some seem to progress more rapidly while others seem to remain stable for years.
The advent of Liver Fibroscan has made a significant change in the way patients with fatty liver are evaluated nowadays. Estimation of fat content is the starting point. Those with very high values need to work hard to get their livers in shape.
The test also measures the stiffness of the liver at the same time and tells whether scarring of the organ has begun. If indeed it has, one needs to get serious and work hard to make sure that the disease does not progress to the stage of liver failure, requiring a liver transplantation.
Another recent finding that research has shown up is that patients with diabetes and fatty liver are at increased risk of developing liver cancer. They often come silently or are incidentally picked up on imaging tests, but progress aggressively over few months. Scientists are debating whether all type 2 diabetics with excess fat in their liver should be monitored periodically with CT scans or MRI scans to watch for early liver cancer.
Diabetes also develops stones in their gallbladders more frequently. It is best to have them removed by a laparoscopic surgery before they cause pain or complications.
Diabetics are very prone to develop Fatty Liver. This condition, earlier thought to be innocuous, has now been seen to progress to liver cirrhosis or liver cancer in a significant proportion of patients. Good control of diabetes with diet, exercise and medications, and maintenance of proper body weight reduces the risk. Screening programs with newer tests help detect and treat liver problems better if done periodically.
By Dr. Gourdas Choudhuri
Dr. Gourdas Choudhuri, Director & HOD, Gastroenterology & Hepatobiliary Sciences, Fortis Memorial Research Institute (FMRI), Gurgaon